Skid steer loaders were first invented about 30 years ago to fill a need for a small highly maneuverable vehicle that was capable of carrying an implement mounted on loader arms. Skid steer loaders are typically small vehicles, on the order of 10 to 14 feet long that rest on four or more wheels, at least two of which being disposed on each side of the vehicle.
In order to turn these vehicles, the wheels on opposing sides of the skid steer loader are driven at different speeds. This causes the faster moving wheels on one side to advance that side over the ground faster than the other side on slower moving wheels. The effect is to turn the vehicle toward the wheels on the slower moving side. Since the wheels are not turnable with respect to the vehicle, the vehicle turns by skidding slightly, hence the name “skid steer loader.” In the extreme case the wheels on one side of the vehicle not only rotate slower than the wheels on the other side of the vehicle but can turn in the opposite direction. When this mode of operation is selected, the skid steer loader will rotate in place about a vertical and generally stationary rotational axis.
This ability to change direction by rotating about an axis within the footprint or perimeter of the loader itself was the primary reason why the skid steer loader achieved its great success.
This mode of turning by skidding places large stresses on the axles of the vehicle. This has, until recently, meant that skid steer vehicles do not use suspensions.
Suspensions are generally preferred for skid steer vehicles however, since they permit the vehicle to travel more easily and stably over the rough terrain of many construction sites. This rough terrain is a particular concern for short and narrow wheelbase vehicles like skid steer vehicles. It is an object of this invention to provide such a vehicle.